add support for wasm32-wasi

sys/build.rs

@@ -1,10 +1,92 @@
 use std::{
     env, fs,
     io::Write,
-    path::Path,
-    process::{Command, Stdio},
+    path::{Path, PathBuf},
+    process::{self, Command, Stdio},
 };
 
+// WASI logic lifted from https://github.com/bytecodealliance/javy/blob/61616e1507d2bf896f46dc8d72687273438b58b2/crates/quickjs-wasm-sys/build.rs#L18
+
+const WASI_SDK_VERSION_MAJOR: usize = 20;
+const WASI_SDK_VERSION_MINOR: usize = 0;
+
+fn download_wasi_sdk() -> PathBuf {
+    let mut wasi_sdk_dir: PathBuf = env::var("OUT_DIR").unwrap().into();
+    wasi_sdk_dir.push("wasi-sdk");
+
+    fs::create_dir_all(&wasi_sdk_dir).unwrap();
+
+    let major_version = WASI_SDK_VERSION_MAJOR;
+    let minor_version = WASI_SDK_VERSION_MINOR;
+
+    let mut archive_path = wasi_sdk_dir.clone();
+    archive_path.push(format!("wasi-sdk-{major_version}-{minor_version}.tar.gz"));
+
+    println!("SDK tar: {archive_path:?}");
+
+    // Download archive if necessary
+    if !archive_path.try_exists().unwrap() {
+        let file_suffix = match (env::consts::OS, env::consts::ARCH) {
+            ("linux", "x86") | ("linux", "x86_64") => "linux",
+            ("macos", "x86") | ("macos", "x86_64") | ("macos", "aarch64") => "macos",
+            ("windows", "x86") => "mingw-x86",
+            ("windows", "x86_64") => "mingw",
+            other => panic!("Unsupported platform tuple {:?}", other),
+        };
+
+        let uri = format!("https://github.com/WebAssembly/wasi-sdk/releases/download/wasi-sdk-{major_version}/wasi-sdk-{major_version}.{minor_version}-{file_suffix}.tar.gz");
+
+        println!("Downloading WASI SDK archive from {uri} to {archive_path:?}");
+
+        let output = process::Command::new("curl")
+            .args([
+                "--location",
+                "-o",
+                archive_path.to_string_lossy().as_ref(),
+                uri.as_ref(),
+            ])
+            .output()
+            .unwrap();
+        println!("curl output: {}", String::from_utf8_lossy(&output.stdout));
+        println!("curl err: {}", String::from_utf8_lossy(&output.stderr));
+        if !output.status.success() {
+            panic!(
+                "curl WASI SDK failed: {}",
+                String::from_utf8_lossy(&output.stderr)
+            );
+        }
+    }
+
+    let mut test_binary = wasi_sdk_dir.clone();
+    test_binary.extend(["bin", "wasm-ld"]);
+    // Extract archive if necessary
+    if !test_binary.try_exists().unwrap() {
+        println!("Extracting WASI SDK archive {archive_path:?}");
+        let output = process::Command::new("tar")
+            .args([
+                "-zxf",
+                archive_path.to_string_lossy().as_ref(),
+                "--strip-components",
+                "1",
+            ])
+            .current_dir(&wasi_sdk_dir)
+            .output()
+            .unwrap();
+        if !output.status.success() {
+            panic!(
+                "Unpacking WASI SDK failed: {}",
+                String::from_utf8_lossy(&output.stderr)
+            );
+        }
+    }
+
+    wasi_sdk_dir
+}
+
+fn get_wasi_sdk_path() -> PathBuf {
+    download_wasi_sdk()
+}
+
 fn main() {
     #[cfg(feature = "logging")]
     pretty_env_logger::init();
@@ -92,7 +174,8 @@ fn main() {
     }
 
     for file in source_files.iter().chain(header_files.iter()) {
-        fs::copy(src_dir.join(file), out_dir.join(file)).expect("Unable to copy source");
+        fs::copy(src_dir.join(file), out_dir.join(file))
+            .expect("Unable to copy source; try 'git submodule update --init'");
     }
     fs::copy("quickjs.bind.h", out_dir.join("quickjs.bind.h")).expect("Unable to copy source");
 
@@ -101,16 +184,50 @@ fn main() {
         patch(out_dir, patches_dir.join(file));
     }
 
+    let mut add_cflags = vec![];
+    if env::var("CARGO_CFG_TARGET_OS").unwrap() == "wasi" {
+        let wasi_sdk_path = get_wasi_sdk_path();
+        if !wasi_sdk_path.try_exists().unwrap() {
+            panic!(
+                "wasi-sdk not installed in specified path of {}",
+                wasi_sdk_path.display()
+            );
+        }
+        env::set_var("CC", wasi_sdk_path.join("bin/clang").to_str().unwrap());
+        env::set_var("AR", wasi_sdk_path.join("bin/ar").to_str().unwrap());
+        let sysroot = format!(
+            "--sysroot={}",
+            wasi_sdk_path.join("share/wasi-sysroot").display()
+        );
+        env::set_var("CFLAGS", &sysroot);
+        add_cflags.push(sysroot);
+    }
+
     // generating bindings
-    bindgen(out_dir, out_dir.join("quickjs.bind.h"), &defines);
+    bindgen(
+        out_dir,
+        out_dir.join("quickjs.bind.h"),
+        &defines,
+        add_cflags,
+    );
 
     let mut builder = cc::Build::new();
     builder
         .extra_warnings(false)
+        .flag_if_supported("-Wno-implicit-const-int-float-conversion")
         //.flag("-Wno-array-bounds")
         //.flag("-Wno-format-truncation")
         ;
 
+    if env::var("CARGO_CFG_TARGET_OS").unwrap() == "wasi" {
+        // pretend we're emscripten - there are already ifdefs that match
+        // also, wasi doesn't ahve FE_DOWNWARD or FE_UPWARD
+        builder
+            .define("EMSCRIPTEN", "1")
+            .define("FE_DOWNWARD", "0")
+            .define("FE_UPWARD", "0");
+    }
+
     for (name, value) in &defines {
         builder.define(name, *value);
     }
@@ -149,7 +266,7 @@ fn patch<D: AsRef<Path>, P: AsRef<Path>>(out_dir: D, patch: P) {
 }
 
 #[cfg(not(feature = "bindgen"))]
-fn bindgen<'a, D, H, X, K, V>(out_dir: D, _header_file: H, _defines: X)
+fn bindgen<'a, D, H, X, K, V>(out_dir: D, _header_file: H, _defines: X, _add_cflags: Vec<String>)
 where
     D: AsRef<Path>,
     H: AsRef<Path>,
@@ -187,7 +304,7 @@ where
 }
 
 #[cfg(feature = "bindgen")]
-fn bindgen<'a, D, H, X, K, V>(out_dir: D, header_file: H, defines: X)
+fn bindgen<'a, D, H, X, K, V>(out_dir: D, header_file: H, defines: X, mut add_cflags: Vec<String>)
 where
     D: AsRef<Path>,
     H: AsRef<Path>,
@@ -200,6 +317,7 @@ where
     let header_file = header_file.as_ref();
 
     let mut cflags = vec![format!("--target={}", target)];
+    cflags.append(&mut add_cflags);
 
     //format!("-I{}", out_dir.parent().display()),
 
@@ -211,6 +329,8 @@ where
         });
     }
 
+    println!("Bindings for target: {}", target);
+
     let bindings = bindgen_rs::Builder::default()
         .detect_include_paths(true)
         .clang_arg("-xc")

sys/quickjs.bind.h

@@ -1,6 +1,6 @@
 // A header which imports the all symbols of the quickjs header but also exports the static atoms.
 
-#include "quickjs.h";
+#include "quickjs.h"
 
 
 #if !defined(EMSCRIPTEN) && !defined(_MSC_VER)